Full on uber-fuzz researched and revealed by a number of stompbox experts around the world. Dragonfly of Soulkitchen FX (Check out the crazy boxes!), David Main of D*A*M FX in the UK and various others all contributed to this great piece of DIY reseach and destroy stompbox mythics. Firstly a demo video of the Buzzaround in action:
Turns out to be very similar to the old 3 Knob Tonebenders. Still worth a build though for some real full on fuzz antics. Here is Dragonfly's scheme and the great Torchy's vero.
Here's a tagboard layout from Sinner of turretboard.org:
And the freestompboxes.org forum thread: http://freestompboxes.org/viewtopic.php?f=19&t=1211
If you want the Buzzaround sound but don't want to have to fiddle around finding three germanium transistors that fit the required gain and leakage requirements check out this Buzzaround-a-like designed by mictester:
I tried this and actually preferred it over my Buzzaround clone - you can get all the original tones and a lot more! Here's mictester's description:
"The original consisted of two stages - a two-transistor amplifier and a distortion stage that could have both the amount of signal sent to it and the bias point adjusted by external controls. The third control was a crude tone control which fed the output. Originally, the output was unbuffered, and the leads and amplifier following would load the unit, and the top end would be rolled off, and often the tone control would have little effect.
The first stage in the sound-alike is just a high input impedance op-amp gain stage. You may wish to increase the gain by increasing the value of the feedback resistor, but it sounds pretty good as shown. In the original, the first stage didn't really have much effect on the sound - it just amplified it enough to drive the following stage into conduction.
The heart of the beast is the germanium transistor stage. Apart from using an NPN transistor, this remains true to the original (why screw up a classic?), and still gives a wide range of sounds from the thin toppy fuzz beloved of sixties bands through to gated spluttery farts, with smooth warm distortion sounds in between!
The final stage is just a buffer - it isolates the tone circuit from the outside world, and allows a full range of control from muffled to glass-shattering!"
And here's a vero layout for the Buzz-a-like by roseblood11 (the layout is verified):
A recommended hfe for that transistor? About 80hfe, you'll need one with a bit of leakage too for it to work properly. Here's the freestompboxes.org forum topic for more info and help: http://freestompboxes.org/viewtopic.php?f=13&t=9401